Physics

E equals mc 2 proved that mass can be converted to energy. But how?

What would happen if a 1kg piece of black hole was suddenly transported to the surface of the earth? Would it retain the properties of a black hole and begin devouring mass that it came close to, sinking into the surface of the earth? Would it expand to something much less dense since it did not have the gravity of the entire black hole to keep it in that dense state? If so, what type of matter would it be? Something else?

quote from the Wikipedia article on "digital physics": http://en.wikipedia.org/wiki/Digital_physics I haven't read the article in detail, although as I understand it, one version (not the original) was given by the great American physicist John Wheeler. Looking at the summary of the article I also see that an extreme version of this is "The Matrix", that we're in the middle of super-gigantic simulation. Without going into detail, I have a notion this is a wrong-headed notion because of Godel's theorem , but I would like to hear from more knowledgeable people than I about the pros and especially cons of this idea.

It will also be helpful if you can give example. Thanks you.

Hi At university my mattress bed keeps slipping off the bed when I sleep on it. I'm trying to find something that would offer friction against the mattress and the metal bed, when placed in between the two. I've tried a rug and that helped but wasn't 100% effective, i'm now using a cotton bath mat and that doesn't work as well as the rug. Will a yoga mat or a PVC mat offer more friction? If not what material will? Many thanks Charlie

I heard reading somewhere saying that if you live in a planet with a weaker gravitational force, you'll live longer. So, say you lived in space your whole life, with no gravity, would this extent your life expectancy significantly assuming health clinics and other necessities and lifes little pleasures were all readily accessible and available and identical in every nature to those we have in planet Earth. If all that's different is that there's no gravity, how long would one live for, in space? This is just another hypothetical question, if humans ever do live in space, in the future.

is there some way in which I can calculate the direction the electrons will go after being ejected from a metal as a result of photoelectric effect?

Is there a sum to work out how hot the point of focusing could get with a parabolic mirror? thanks, matt

Hello everyone, Ok generally what do they mean when they say vasodilation in periphery lead to reduction in blood pressure? Do I have to think of this as expanding the size of a fluid filled container so less fluid splashes againts the walls reducing pressure. Or do I have to think of this like a circuit where decreasing the resistane of a resistor results in decreased pressure just upstream of that resistor. Thank you

I was wondering, with AC, if the charges are constantly changing direction, wouldn't that mean the current would move slowly, create vast amounts of heat energy and overall wouldn't be very effective/efficient... So how exactly is it better than DC and how does a step-up transformer with AC allow it to be transfered long distances without loosing as much energy ? Also, do power lines have periodically set up step-down transformers which aid the transformation of AC and if so why can't it be done with as much efficiency with DC ? thanks.

Hi, i was wondering if the right-hand rule - as in the one where your fingers are the field, the thumb is the current and the palm is the force, can only be applied to anything involving electricity or can it just be anything involving fields ?

does anyone know how research is getting on with fusion reactors? how much progress they're making?

On the primary I can produce 120 volts and on the secondary i can create 240 volts. I placed a motor that will used up 120 volts on the secondary wire-which will turn the voltages of the current back to 120 volts, and then I connected that wire back to the primary. Wouldn't that creates perpetual motions?

greetings colleagues! i need a liquid which is a good heat conductor but not a conductor of electricity ,and also must be fluid. i need that liquid for a research of a new project at uni. by the way the cheaper liquid is better what's ur offer or how and where can i find it? thanks fg

when light slows down in a glass tube, will its wavelengths change or stay the same? since light slows down in a glass/a different medium, shouldn't its wavelengths changes accordingly to it?

Hi, If you have a simple capacitor made of two identical metal plates. After you put a charge on it... 1. does the negative plate becomes any heavier (greater mass) than the positive one? (For the difference in number of electrons inside. Or am I missing some other effects.) 2. does the negative plate becomes any warmer (higher temperature) than the positive one? (Because I imagine electrons as a 'gas' inside metal -> 'pressure' is reduced on the positive plate, and increased on the negative.) Thanks.

Hello everyone! I have a short question pertaining to electricity. I know that the potential difference across a component is directly proportional to the resistance. But does the current affect potential difference? What I mean is that, if the current were to increase, will the potential difference increase?

Just a passing thought: We know of several types of fields electromagnetic/gravitational,etc.Each one of these fields has some fundamental property which is required to create it (there are exceptions e.g. light is a combination of fields independent of a producing particle) .For example charge is required for an electric field,mass for a gravitational field,other types of fields also exit for other attributes. But is it possible to synthesize a brand new field (even theoretically) not simply make a composition of existing attributes. please note : I understand that fields are representations of interactions, and under this perspective my question still stand…

I was wondering, with Einstein's equations. Are they just like (basic) algebraic equations in maths, where you solve for the unknown variable, hence the "solutions" to Einstein's equations. Except that they are very complex and solutions for them revolve around (frontier) theoretical concepts in physics.. But why would Einstein have not worked it all out when he was doing them.. or is it that there are variables for which we are only now discovering and accounting for that he didn't.. etc

Do neutrons attract, repel, or have no effect on each other?

Although it is commonly accepted that physical laws and values of fundamental constants are the same throughout our universe, a recent finding, in which the fine-structure constant alpha has been found to vary by a small amount (1 part in 100,000) going from one end of the universe to another, i.e. surprisingly the variation seems to be unidirectional. Here's the web link to the news article on this: http://www.gizmag.com/laws-of-physics-may-vary-throughout-the-universe/16329/ Comments? (I'd wonder myself about some sort of systematic experimental error, but the article doesn't give details about the experiment.)

if someone were to melt down the ore thatis used to make magnets into a sphere, is it possible to make all the negative poles pointed toward the center and create a monopole on the outside? ( I know that the negative poles would repel each other, but if some thing had a strong enough pull, could it result in a monopole?)

What is really a string theory? What are the fundamental principles and how the final theory will look like (in terms of strings or other fundamental degrees of freedom)? what are the major obstacles (inherent to string theory) preventing us from identifying these underlying principles and constructing this unique framework or theory?

I think time and space are intertwined and cannot be separated. To confirm/verify, let me pose the following questions: 1. Is there some experimental data that proves that time is actually another dimension? Or maybe theoretical explanation? 2. Had anyone explained in detail what time is and why it is what it is? Or we just rely on some intuitive understanding of "time"?

the magnetic field of a magnet forms two half spiral that comes out from the N to the S but an electron's was a spiral that warps around itself, Why are there field lines different? Shouldn't they be the same since a magnet's field lines is basically made of electrons facing the same way?